The field of the present invention is the production of human monoclonal antibodies through fused hybrid cells. In particular, the present invention relates to novel trioma producers of human monoclonal antibodies and to murine-human hybridoma immortalizing cell lines suitable for their preparation.
Human antibodies have been used both for diagnostic and therapeutic purposes for a number of years. Diagnostic techniques include blood typing for transfusion (Yankee, R. A., et al, New Eng. J. Med., 281:1208 (1969)); or transplantation (Grumet, F. C., et al, Hum. Immunol, 5:61 (1982)). Therapeutic applications include prophylaxis of Rh hemolytic disease, (Nusbacher, T., et al., New Eng. J. Med., 303: 935 (1980); and injection of anti-varicella zoster plasma (Grose, C., Human Herpes Virus Inf. (1982) Marcel Delcker, N.Y.). The oldest technique for obtaining these antibodies is isolation from immune serum. However, the small concentration of the antibody of desired specificity among those which are generally present in serum presents a serious drawback.
More recently, the production of human monoclonal antibodies has become possible and these may serve as tools in diagnostic testing and in therapy. Two major approaches for the production of human monoclonal antibodies (Mab's) have been used: direct immortalization of immunized lymphocytes with Epstein-Barr Virus (EBV) and Mab production by hybridomas formed between immortalized human B cell lines (EBV), lymphoblastoid, or human or murine myelomas, and human B lymphocytes from an immunized host. Neither of these approaches has proved entirely satisfactory.
It is common experience among practitioners in the art that EBV transformation, while successful in forming Mab-secreting cultures, will often fail to provide antigen specific EBV transformed cells which have sufficiently long life spans to provide reliable sources of the desired antibodies (Kozbor, D., et al, Hybridoma, 1:323 (1982). Thus, this method fails to provide reliably for antibody production over extended periods. Previously produced hybridomas between immunized human B cells and appropriately drug marked mouse or human myeloma or human lymphoblastoid cell lines have suffered from low frequency of hybrid formation in the case of human-human hybridizations (Olsson, L., et al., Proc Nat Acad Sci, 212:767 (1980)) or chromosomal instability in the case of murine-human hybridomas (Nowinski, R., et al., Science 210:537 (1980), Lane, H. C., et al, J Exp Med, 155:333 (1982)). (Murine-murine hybridomas are stable, but the antibodies produced are immunogenic if used in passive therapy.)
An immunized experimental animal can sometimes serve as a source for specific antibody-secreting B cells to provide the immunized lymphoid member of the hybridoma. This method cannot be used, however, to provide reagents for HLA or other blood type testing since when human antigens are injected, the plethora of antibodies elicited is mostly immunoreactive to antigens common to all humans, and the desired antigen-specific antibody is formed only as a very small percentage of the total response. Further, these non-human antibodies can themselves result in an adverse immune response if injected for human therapy.
The problems associated with human monoclonal antibody production have been greatly ameliorated by the immortalizing hybridoma and resultant triomas of the present invention. The present invention, thus, provides a means for producing human antibodies of the desired specificity dependably and over long periods of time, using a stable, immortal Mab producing source.